1. Field of the Invention
This invention pertains to attachments for use with rotary lawn mowers to convert the mowers into chopping devices suitable for chopping leaves, twigs and small branches.
2. Description of the Prior Art
Various types of attachments are known for attempting to convert a rotary lawn mower to a chopping or mulching device. Some of these devices are illustrated in U.S. Pat. Nos. 3,527,278, 2,706,372, 3,790,094; 3,286,376 and 3,808,782. None of these devices are satisfactory since it is believed that they do not provide sufficient high-torque shearing action nor adequate residence time of the material in the housing for effective chopping. For example, U.S. Pat. No. 3,808,782 discloses an attachment removably mounted on the upper portion of a mower housing. Materials inserted through the chute 28 are cut solely by the rotary blade, which is generally ineffective to chop larger (up to 3/4 inch in diameter) twigs. Furthermore, the bottom of the housing opening is left open so that some of the materials will be immediately ejected without sufficient residence time for complete chopping.